1. Field of the Invention
The invention relates to a process and an apparatus for the superfine spraying of dispersive systems in superfine particle form.
2. Prior Art
German OS No. 27 24 931 discloses an apparatus for the spraying of dispersed systems, especially suspensions. The apparatus contains a dispensing head having an orifice nozzle, a die disposed inside of the dispensing head and shiftable through the orifice nozzle aperture and possibly a sieve insert bottom disposed between an inlet for the dispersive system and the orifice nozzle, with a stripping arrangement for the sieve insert. In order to operate satisfactorily with such apparatus and in order to obtain a uniform spray pattern, it is necessary to maintain a minimum orifice nozzle diameter of 0.3 mm and a minimum operating pressure of 20 bar. Such means that successful operation cannot be obtained if the throughput goes below a certain value. Such also means that, in the case of spraying, the dispersive systems are applied as relatively thick films.
When spraying suspensions containing graphite as a dispersing material, larger portions of polymers such as alkylene polymerizates, dispersants and stabilizers, suspended as a rule in water, through an air atomizing nozzle, there exists the danger that the polymer especially tends to form a film and resinificate. Such suspensions are described in German OS No. 24 50 717 as high temperature lubricants.